Abstract:Vickers microhardness of TA15 titanium alloy after equal channel angular pressing (ECAP) and its variation was investigated. The results indicate that the microhardness is increased observably after ECAP, and the microhardness level of the outer layer is slightly higher than that of the core in the same cylinder sample. The microhardness of ECAPed alloy is closely related to microstructure distortion, dislocation density, grain size and phase composition. There is a decrease in microhardness with the increasing pressing temperature below Tβ. As a result of the acicular martensite precipitation, the microhardness after ECAP above Tβ is much higher than that below Tβ. A lower die angle means a better hardness. The microhardness increases first and then remains at a certain level with the increasing passes, while the route effects on hardness are related to the pass number and the refinement effects. The annealing after ECAP can effectively reduce the microhardness